1. Field of the Invention
One aspect of the invention disclosed in application Ser. No. 345,197 which is expanded upon in this application is the feature whereby a scanning beam of energy is made to impinge upon a target screen comprising optical fibers or light pipe members which are used to transmit optical radiation across the target screen. Specifically, optical index radiation is transmitted parallel to the target screen generally from its interior regions to its periphery where it is used for beam-indexing purposes to control the generation of multi-color displays.
Another aspect of the invention disclosed in Serial 345,197 which is expanded upon herein relates to the generation of large screen displays wherein a scanning optical beam excites a line-screen target placed at a distance from the source of the optical beam. In particular, one embodiment is envisaged wherein a screen is placed against or mounted on a wall, as a picture in a frame, to be excited by a scanning optical beam in order to produce a color picture. Index radiation is developed, to synchronize the excitation of the target screen, and is concentrated for transmission either through the air or via electrical or optical cables to a color signal processor which modulates the scanning beam. If a cable configuration is used, it is contemplated that the cable may be run across the ceiling of the room as an added convenience.
2. Description of the Prior Art
Beam-index color cathode ray tubes have been proposed by many workers, in many countries, and several working prototypes have been described in the open literature. Generally speaking they have not been characterized by high brightness which rules out their use in projection television schemes. As a consequence most low cost, large screen color displays have resorted to the use of three cathode ray tubes, each developing a different color picture which is projected in careful registration upon a viewing screen. Several high cost projection systems have been developed, and some marketed commercially, which rely on phase gratings, and optically deformed surfaces but these are not related to the instant invention except as to the final result achieved, namely, a large screen full color display operating in the television mode. See, for example, True U.S. Pat. No. 3,730,992.
Another system for a large screen television type raster scanned display is typified by a three beam laser system equivalent to the three CRT combination referred to above. Pinnow et al U.S. Pat. No. 3,652,956 describes a variation of this type of display in which the red color is produced at the target screen.
To applicant's knowledge, there is no prior art which describes the use of a line-screen beam-index display system which generates a large screen full color display by optical scanning as set forth in applicant's copending application Ser. No. 345,197.
Furthermore, with respect to either direct view or projection displays the prior art of others is silent insofar as applicant's teachings are concerned wherein the index radiation generated at the viewing screen is detected by the scintillation process, thereby to capture a large amount of the index radiation. Light pipe transmission is utilized in conjunction with the scintillation process and this too is believed to be set forth in television type raster scan color display apparatus solely by applicant in this application, and in his prior teachings.
The search for a successful low cost projection type color apparatus has persisted for a long time. See, for example, Von Ardenne U.S. Pat. 2,265,657 which was filed 35 years ago, in 1939. And then note the recent comment attributed to the representative of a leading international producer of color television receivers which is reproduced here:
The Prime Minister's statement that no import quotas would be placed on colour television sets coming into Australia has been welcomed by the senior managing director of the Sony Corporation of Japan. * * * Mr. Yoshie said in ten years consumers would be able to purchase television sets ranging from one inch to wall size.
Abc newsroom PA2 Canberra, A.C.T., Australia PA2 7:00 p.m., 27 April 1974
The instant invention describes a system which can be manufactured to yield these results immediately.